A battery-free electric mosquito swatter, comprising a flat swatting portion (1), a handle (2), a control circuit board (3), and a mechanical energy-based power generation device (5). The flat swatting portion (1) consists of a swatter frame and a swatter net. The flat swatting portion (1) is connected to the handle (2), the control circuit board (3) and the mechanical energy-based power generation device (5) are disposed within the handle (2), and the swatting net and the mechanical energy-based power generation device (5) are electrically connected to the control circuit board (3). The mechanical energy-based power generation device (5) comprises a hand squeeze member (51), a gear transmission mechanism, and a power generator (57). The hand squeeze member (51) is provided with a curved gear rack (511) meshing with an input gear of the gear transmission mechanism. An output gear of the gear transmission mechanism drives a rotating shaft of a rotor of the power generator (57) to rotate. The power generator (57) is electrically connected to the control circuit board (3). The handle (2) is provided with a discharge button switch (4) used to short a positive and negative electrode of the swatter net. The electric mosquito swatter of the present invention does not require a battery, lowers a use cost, and reduces environmental pollution caused by waste batteries. In addition, the present invention provides a reasonable and reliable overall design and safety during use, has a long service life and a low cost, and is easy to assemble and ready for use immediately after squeezing, thus providing convenience and fun during use.